This June 4 will mark the 23rd anniversary of the brutal crackdown on the 1989 Tiananmen Square protests, when hundreds of demonstrators were killed by soldiers on the streets of Beijing. Twenty-three is not a special number. In Hong Kong, about 2,100 people took part in the annual Tiananmen memorial march, down from 8,000 during the 20th anniversary in 2009, organizers told the South China Morning Post. Protesters’ signs carried messages calling on China’s central government to overturn the official condemnation of the 1989 protests and exhorting the people of China to not forget.

On the mainland, where public discussion of the events from over two decades ago is strictly circumscribed, there are signs that the 1989 massacre is disappearing down a memory hole. In 2007 a newspaper in Sichuan ran a one-line classified ad paying tribute to the victims of June 4th, as the crackdown is known in Chinese. When the censorship breakdown was investigated later, one explanation offered was that the newspaper’s young advertising clerk had never heard of the events of June 4th. A full explanation is difficult to come by when searching the Internet in China. So the clerk bought the ad buyer’s explanation that June 4 was a “mining disaster.”

But for every story of someone in China who didn’t know about the Tiananmen crackdown, there is one of someone who couldn’t forget. Yesterday the Tiananmen Mothers, a support group of 1989 victims’ kin, announced that one of the members committed suicide on Friday. Ya Weilin was 73; his 22-year-old son Ya Aiguo was shot in the head by troops near Gongzhufen in western Beijing on June 3, 1989. In an obituary of the elder Ya, the Tiananmen Mothers said the retired employee of a state-run nuclear institute hanged himself in a newly built underground parking garage. Ya had recently written a note stating that his grievances over his son’s death hadn’t been answered in over 20 years and that he would “fight to his death,” according to his obituary.

Last month Hong Kong’s Ming Pao newspaper reported that Li Yujun, a peddler convicted of arson after the protests, was released after spending 23 years in prison. Li, who was then 22, had set fire to a fuel truck in an attempt to block the approach of People’s Liberation Army troops toward the center of Beijing. In 2009, Human Rights in China compiled a list of 45 people, almost all farmers or blue collar workers, who remained in prison on June 4th–related convictions.